accepted research article

East and Central African Journal of Surgery

Title: Anaesthetic challenges in omphalocele repair at a tertiary hospital in Ibadan, Nigeria: A review of medical records from January 2008 through December 2017

Authors: Tinuola A. Adigun, Olakayode O. Ogundoyin, Emily E. Awana, Dare I. Olulana, Taiwo A. Lawal

Received: 11-Apr-2020

Revised: 4-Oct-2020, 22-Dec-20

Accepted: 11-Jan-2021

Published: 13-May-2021

Citation: Adigun TA, Ogundoyin OO, Awana EE, Olulana DI, Lawal TA. Anaesthetic challenges in omphalocele repair at a tertiary hospital in Ibadan, Nigeria: A review of medical records from January 2008 through December 2017 [published online, 2021 May 13]. East Cent Afr J Surg. 2021. Competing interests: None declared This accepted article will undergo further copyediting, typesetting, and proofreading before inclusion in a forthcoming issue of the East and Central African Journal of Surgery as the final version of record. The finalized article will differ from this version, and errors may be detected during the production process. © T.A. Adigun et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly cited. To view a copy of the license, visit http://creativecommons.org/licenses/by/4.0/.

ACCEPTED RESEARCH ARTICLE

East and Central African Journal of Surgery 1

Anaesthetic challenges in omphalocele repair at a tertiary hospital in Ibadan, Nigeria: A review of medical records from January 2008 through December 2017

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ORIGINAL RESEARCH

Anaesthetic challenges in omphalocele repair at a tertiary hospital in Ibadan, Nigeria: A review of medical records from January 2008 through December 2017 Adigun TA 1, Ogundoyin OO2, Awana EE1, Olulana DI2, Lawal TA2

1. Department of Anaesthesia, University College Hospital, Ibadan, Nigeria.

2. Department of Surgery, University College Hospital, Ibadan, Nigeria.

Correspondence: Dr Olakayode O. Ogundoyin

Department of Surgery, University College Hospital, Ibadan, Nigeria

Email: [email protected]

Running Title: Anaesthesia management of Omphalocoele

Sources of Funding: None

Abstract

Background: Omphalocele is the commonest congenital anterior abdominal wall defect. It is associated with

herniation of abdominal contents and the challenges it pose to the surgeons, anaesthetists and neonatal intensivists

are daunting especially in the developing country.

Methods: This was a retrospective study of the challenges encountered during the perioperative management of

neonates who had repair of omphalocele over a 10-year period. Information retrieved were demographic data,

perioperative complications, anaesthetic techniques and outcome. These were collected in a proforma and

analyzed.



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Results: There were 57 neonates comprising 34 (59.6%) males and 23 (40.4%) females with male: female of 1.5:1.

They presented between 1st and 14th day of life with a mean age of 2.7±3.6 days and mean birth weight of 3.06 ±

0.54 kg. There were 33 (57.9%) major and 24 (42.1%) minor omphaloceles. About 77.2% of patients had American

Society of Anaesthesiologists (ASA) Physical Status Classes 1 and 2 at the time of surgery, 15 (26.3%) children

had associated comorbidities which included sepsis 10 (17.5%), anaemia 3 (5.3%) and jaundice 2 (3.5%).

Associated congenital anomalies were noticed in 10.5% of cases. All neonates had general anaesthesia with

relaxant technique. Intraoperative challenges encountered were difficult intubation 5 (8.8%), hypothermia 7

(12.3%), tachycardia 37(64.9%) and bradycardia 3 (5.3%). Postoperatively, 15 (26.3%) neonates needed

mechanical ventilation and intensive care management, 43 (75.4%) neonates survived while 14 (24.6%) died.

Conclusions: General anaesthesia is the conventional method for omphalocele repair, it is safe but not without its

challenges. These challenges should be anticipated, and facilities should be in place to manage them.

Keywords: anaesthesia, challenges, omphalocele, repair, Nigeria

Introduction

Omphalocele is the most commonly encountered congenital anterior abdominal wall defect. It is a defect in the

midline with herniation of abdominal content through an extra embryonic part of the umbilical cord.

The aetiology is due to failure of the four embryonic folds to meet in the midline to form umbilical ring resulting

in ventral abdominal wall defect of varying degree1. Omphalocele can be minor or major. It is classified as

omphalocele minor when the defect is less than 5 cm in diameter with the sac containing only bowel loops and

major when the size of the defect is more than 5 cm with the covering sac containing liver, spleen, etc. or has

associated major congenital anomalies2,3. However, omphalocele has been re-classified to include the

‘intermediate’ group when the defect is more than 5cm in diameter with no associated major anomaly and bedside

reduction can be achieved without compromise. Such omphaloceles can be closed primarily2.

Its incidence in Nigeria is not known but the world incidence varies from 1:6000 live birth to 1:32000 when live

birth and still born are considered 4.



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Omphalocele can occur as an isolated finding or in association with a number of congenital abnormalities like

cardiac defect, genitourinary abnormalities and chromosomal abnormalities like Trisomy 13, 15, 18 & 21 and

other syndromes like Beckwith Wiedemann syndrome5.

Surgical management of omphalocele includes primary closure of the defect or staged closure with silo6. The

anaesthetic management may be challenging and require anticipation of problems such as prematurity, low birth

weight, hypothermia, sepsis, dehydration, presence of associated congenital anomalies and small abdominal

cavity7. Postoperatively, the abdominal cavity may be too small to accommodate the eviscerated organ when they

are returned back into the abdomen with consequent respiratory failure.

Advances in anaesthesia and neonatology have greatly improved the survival of these neonates. Communication

and cooperation between the surgeons, anaesthesiologists and neonatologists are of utmost importance to ensure

the best possible outcome. The aim of this study was to outline the challenges encountered peri-operatively and

outcome of surgical management of neonates during omphalocele repair in our institution.

Methods

This was a retrospective review of records of all patients with omphalocele repair at the main operating room of

the University College Hospital, Ibadan over a ten - year period from January, 2008 to December 2017. Neonates

with gastroschisis were excluded from the data. The operating room records were reviewed to identify all cases of

omphalocele operated during the period. The case records of the patients identified were then reviewed. The data

retrieved included age, gender, birth weight, size of the sac, associated congenital anomaly, American Society of

Anaesthesiologists (ASA) physical status, induction technique and muscle relaxants used, type of surgery,

intraoperative events and postoperative complications, length of hospital stay, admission to the Intensive Care

Unit (ICU) and final outcome. Ethical approval for the study was obtained from our Institution Ethical Review

Committee (UI/EC/18/0461). Data collection and analysis were conducted in accordance with the ethical

standards of 1964 declaration of Helsinki and its later amendments.

Anaesthetic technique

The technique of anaesthesia for all neonates was general anaesthesia with endotracheal intubation, muscle

relaxation and intermittent positive pressure ventilation. The cadre of anaesthesia providers were physicians,



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consultants that were formally trained in paediatric anaesthesia and senior registrars that have spent at least four

years in postgraduate training. General anaesthesia was induced with either intravenous ketamine or inhalational

agent; halothane or sevoflurane and tracheal intubation were facilitated with suxamethonium. The sizes of

endotracheal tubes for intubation were between 2.0 mm and 3.5 mm in internal diameter. All neonates were

premedicated with atropine to reduce secretion and increase the heart rates. Controlled ventilation was used in all

patients and anaesthesia was maintained with Isoflurane, 100% of Oxygen and Atracurium. Analgesia was with

Fentanyl and Paracetamol. Drugs were given in dose per kilogram body weight. Monitoring included pulse

oximetry, electrocardiograph, capnograph, temperature, urinary output and blood glucose. Postoperatively, after

reversal of the neuromuscular blockade those with delayed recovery or respiratory distress were transferred to the

general Intensive Care Unit (ICU) whereas those with full recovery with no distress were transferred to the

recovery room.

Statistical analysis

Data were analyzed using Statistical Package for Social Sciences (SPSS) version 20.0, Chicago Illinois. Continuous

data were presented as means ± standard deviation whereas categorical variables were presented as frequency and

percentages. The level of significance was set at p value of < 0.05.

Results

A total number of 57 neonates with omphalocele had surgical repair during the study period comprising 34

(59.6%) males and 23 (40.4%) females with male: female of 1.5:1. The age at presentation ranged from 1 day to 14

days with a mean age of 2.70 ± 3.26 days. The mean birth weight was 3.06 ± 0.54 kg, 5 (8.8%) neonates had birth

weight less than 3.0 kg. There were 33 (57.9%) major and 24 (42.1%) minor omphaloceles at presentation. Four

(7.0%) patients had American Society of Anesthesiologist's (ASA) Physical Status Class 1, 40 (70.2%) had ASA

Class 2, 11 (19.3%) had ASA Class 3 and 2 (3.5%) patients had Class 4. More than 90% of the mothers resided in

the urban community and only two mothers had prenatal ultrasound diagnosis of omphalocele. (Table 1)

Ten (17.5%) neonates had ruptured omphalocele and sepsis was the commonest preoperative comorbidities in 10

(17.5%) neonates, anaemia in 3 (5.3%) and jaundice in 2 (3.5%) neonates. Other associated congenital anomalies

were congenital heart disease, Beckwith Wiedemann syndrome and intestinal atresia in 2 (3.5%) neonates each.

(Table 2)



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Forty (70%) neonates had rapid sequence induction while 17 (30%) had inhalational induction. All but 5 (8.8%)

patients had primary closure of omphalocele with or without closure of the facial. Of the 5 patients that did not

have primary closure, a silo was constructed for them and these were the patients that had rupture of omphalocele

at presentation.

Intraoperative complications recorded were difficult intubation in 5 (8.8%) neonates, hypothermia in 7 (12.3%),

tachycardia in 37 (64.9%) neonates (heart rate >160 /mins) and bradycardia in 3 (5.3%) neonates (heart rate <

100/mins). (Table 3)

Post-operative complications included respiratory failure in 7 (12.3%) neonates, delayed recovery in 8 (14.0%),

wound infection in 6 (10.5%), burst abdomen in 2 (3.5%) and persistent hypoglycemia in 1 (1.8%) neonate. (Table

4)

Ten neonates were admitted into the general ICU and mortality was recorded in 14 (16.9%) patients. The mortality

included the 5 neonates that had ruptured omphalocele with silo construction, sepsis was observed to be the major

cause of death in them. The length of hospital stay ranged from 7 to 30 days.

Discussion

Omphalocele is the commonest of the anterior abdominal wall defects encountered in surgical practice. There

were 57 cases operated over a 10 - year period making approximately 6 cases per year, this is similar to an earlier

report by Ihekwaba from the same center who reported 33 cases over a five- year period from 1973 to 19788.

However, a higher figure was reported in Benin Nigeria with 96 cases over 10 years making the abnormality of

public health concern9.

Surgical treatment is often not considered an emergency unless the covering sac is ruptured therefore; all neonates

went through a detailed history, physical examination, laboratory and radiological investigations to rule out other

congenital anomalies before anaesthesia.

Sepsis, the commonest (17.5%) preoperative complication observed on the patients is lower than 37.5% reported

by Abdur-Rahaman et al.10, this may be due to unhealthy care of the intact sac which can easily be soiled by faeces



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and urine. Sepsis is believed to contribute significantly to increase morbidity and mortality in the management of

omphalocele9. The avascular sac is easily infected despite proper preoperative antibiotic therapy8.

Children presenting for repair would have already been resuscitated preoperatively due to dehydration and

electrolyte loss from exposed viscera as was done for our patients7. Fluid and electrolytes deficit were corrected

preoperatively and maintenance crystalloid fluid at 4ml/kg/hour was continued into the intra and postoperative

periods.

The anaesthesized neonate is at risk of hypothermia. The finding of hypothermia in this series is similar to findings

from previous reports7,10. These patients have less insulator subcutaneous fat in addition to loss of heat from the

exposed gut. Efforts were made to maintain normothermia in these babies by covering the sac with warm saline

soaked gauze, transferring them with incubator to the operating room. The problem of hypothermia may be

compounded by cold operating room environment and dry anaesthetic gases. Heat conservation strategies we

adopted include placing the neonates on warm mattress and increasing the operating room temperature in

addition to warming the intravenous fluid and wrapping up the neonates.

Hypoglycemia is a common problem in neonates due to so many factors which included sepsis and hypothermia

but this could be worsened in a patient with associated Beckwith Wiedemann syndrome preoperatively7, hence

blood glucose was monitored in all the neonates with omphalocele studied in addition to standard monitoring in

anaesthesia. The two neonates with Beckwith Wiedemann syndrome had hypoglycaemia which was corrected.

Glucose containing fluids were commenced preoperatively and continued into the post-operative period.

General anaesthesia with endotracheal intubation and muscle relaxant is the usual anaesthetic technique of choice

during surgical repair of omphalocele in our setting. However, general anaesthesia with regional techniques like

caudal and spinal block11 and combined spinal epidural12 have been reported by some authors.

Intraoperative opioids are generally avoided in neonates due to the fear of opioid induced respiratory depression

with increased need for postoperative ventilation13. Remifentanil which is not always available can be used as it is

preferred to more commonly available fentanyl because it is an ultra-short acting drug and is well tolerated by

neonates.



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Non - depolarizing muscle relaxants are better avoided in neonates because they are more sensitive to its effects

due to reduced release of acetylcholine from immature motor neurons14. However, muscle relaxation is necessary

for optimum closure of the abdominal defect and intubation is necessary to protect the airway against the risk of

aspiration. Cis - atracurium is preferred to atracurium (which is more available in this environment) as cis -

atracurium produces a more predictable duration of action15.

Rapid sequence induction was employed in some neonates in this series when they were at risk of aspiration at

induction of anaesthesia as a result of full stomach while some neonates with minor omphaloceles had inhalational

induction with halothane or sevoflurane especially when the patient was stable and fit. Intravenous induction

versus gas induction remains controversial in neonates with omphalocele16.

Difficult intubation as observed in some neonates is a common challenge, it occurs in 10% of patients with

craniofacial anomalies17 and incidence increases in those with associated syndrome like Beckwith Wiedemann

syndrome. Expert airway management is however essential for safe and effective administration of general

anaesthesia. The anatomical airway peculiarities of the neonates including long and floppy epiglottis with

relatively large tongue add to the incidence of difficult intubation.

Surgical treatment modalities of omphalocele include primary closure of the defect and staged repair using silo6.

The postoperative management is however a challenge as primary closure is often complicated with respiratory

distress as a result of increased intra-abdominal pressure making extubation difficult16. Measuring the respiratory

airway pressure may be used as an indirect method of measuring intra - abdominal pressure after primary closure

of the defect18 and surgeons were advised to reduce the abdominal pressure or staged the repair. Another indirect

method of measuring the intra-abdominal pressure is the measurement of the intra-vesical pressure and if the

pressure is less than 20 mm H2O the patient can be extubated19.

Patients with delayed recovery and respiratory distress after surgery are usually managed in ICU for mechanical

ventilation and postoperative monitoring to ensure good outcome. The lack of well - equipped standard Neonatal

Intensive Care Unit (NICU) poses a great challenge to successful management of surgical neonate and is one of

the factors that have contributed to the high morbidity and mortality in neonatal surgery experienced in Nigeria

and other low and middle - income countries20.



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The practice of neonatal anaesthesia in our centre has improved over the last decade from postoperative manual

ventilation in the first 1 to 2 years of this study to mechanical ventilation, provision of modern equipment, safe

drugs administration and structured training of physician paediatric anaesthetists. The latter years witnessed a

change from the use of manual ventilation to mechanical ventilation and this has impacted on the outcome of

procedures including paediatric surgical cases. As with other major centres in the country20, the major challenge

in our centre is the lack of a dedicated NICU and neonatal ventilator as these neonates are still nursed in the

general ICU where adult equipment are used for them. Thus there is marginal improvement generally in

morbidity and mortality in neonatal surgery including repair of omphalocele.

The survival of neonates with omphalocele in the developed countries has been attributed to the availability of

NICU, parenteral nutrition and various requisite equipment needed to support the post-operative intensive care

of these neonates.

The observed mortality rate of 16.9% is lower than the rate of 22.9% and 32.4% reported by Osifo DO et al9 and

Abdur –Rahman et al10 in Nigeria respectively. It is also significantly lower than the reported rate of 64% by an

earlier study carried out about four decades ago in our centre8.

Respiratory insufficiency was observed to be largely responsible for the mortality recorded in this study. The use

of silastic silo for staged repair of the omphalocele may help to reduce the challenges of post-operative respiratory

insufficiency.

Conclusions

Omphalocele repair is a challenge to both the surgeons and the anaesthetists in the developing country. These

neonates may present with sepsis, hypothermia, fluid and electrolyte imbalance and hypoglycemia these had to be

corrected before the surgery. General anaethesia is a safe and effective technique for surgery but problems of

difficult intubation, drug metabolism and postoperative respiratory distress should be anticipated. The addition

of neonatal ventilator, neonatal intensive care and parental nutrition to the present protocol should reduce

morbidity and mortality in this high-risk group in the future.



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References

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2. Adeniran JO, Abdur-Rahaman LO, Nasir AA. Should Omphalocele be re-classified? East Centr Afr J Surg 2011;16(2): 25 – 31.

3. Sowande OA, Adejuyigbe O, Ogunrombi A, Usang UE, Bakare TI, Ajai OT, Abubakar AM. Experience with Exomphalos in a Tertiary Health Centre in Nigeria. Afr J Paediatr Surg 2007;4(2): 56 – 60.

4. Munkonge L. Challenges in the management of omphalocele at University Teaching Hospital, Zambia. East & Central Afr J Surg 2007; 12: 126-130.

5. Chirdan LB, Ngiloi PJ, Elhalaby EA. Neonatal surgery in Africa. Semin Pediatr Surgery 2012 : 21(2) 151-9

6. Pacilli M, Spitz L, Kiely EM. Staged repair of the giant omphalocele in the neonatal period. J Pediatr Surg 2005 ;40 785-88.

7. Pani N, Panda CK. Anaesthetic considerations for neonatal surgical emergencies. Indian J Anaesth 2012; 56(5) 463-469.

8. Ihekwaba FN. Omphalocele: experience in the African tropics. Postgrad Med J 1981; 57: 635-639.

9. Osifo OD, Ovueni ME, Evbuomuwan I. Omphalocele management using Goal oriented classification in African cenre with limited resources . J Trop Paed. 2011;57(4): 286-288.

10. Abdur-Rahman L, Abdulrasheed N, Adeniran J. Challenges and outcomes of management of anterior abdominal wall defect in a Nigerian tertiary hospital. African J Paediatr Surg. 2011;8(2):159–63.

11. Tobias JD. Spinal anaesthesia in infant and children. Paediatr Anaesth 2000;10: 5-16.

12. Somri M, Tome R,Tanovski B. Combined spinal epidural in abdominal surgery in high risk neonates and infants Paediatric Anaesth 2007;17: 1057-65.

13. Niesters M, Overdyk F, Smith T, Aarts L, Dahan A. Opioid induced respiratory distress in paediatrics: A review of case of case reports. BJA 2003;110;(20175-182.

14. Wareham AC, Morton RH, Meakin GH. Low quantal content of the end plate potential reduce safety factor for neuromuscular transmission in diaphragm of the newborn rat. Br J Anaesth.1994;72: 205-9.

15. Anderson BJ, Allegaert K. The pharmacology of anaesthetics in the neonate. Best Pract Res Clin Anaesthesiol 2010; 24: 419 – 31.

16. Hiller SC, Krishna G. Neonatal anesthesia. Semin Pediatr Surg 2004;3:142-51.

17. Adenekan AT, Faponle AF, Oginni FO. Anaesthetic challenges in orofacial cleft repair in Ile Ife, Nigeria. Middle EastJournal of Anaesthesiology 2011; 21(3) 343-349.

18. Banieghbal B, Gouws M, Davies MR. Respiratory pressure monitoring as an indirect method of intraabdominal pressure measurement in gastroschisis closure. Eur J Pediatr Surg. 2006 ;16(2):79-83. https://doi.org/10.1055/s-2006-924051. PMid:16685611 13

19. Rizzo, A and C Davis, P and R Hamm, C and Powell, Randall, Intraoperative vesical pressure measurements as a guide in the closure of abdominal wall defects. The American Surgeon. 1996; 62:1926.

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Table 1: Demographic characteristics of the neonates Variables Number =57 %

Gender Male 34 39.6

Female 23 40.4

Mean Age ± SD ( days) 2.7±3.26

Mean birth weight ± SD

(kg)

3.06±0.54

Types of Omphalocele

Major

33

57.9

Minor 24 42.1

ASA 1 4 7.1

ASA 2 40 70.1

ASA3 11 19.3

ASA 4 2 3.5

ASA – American Society of Anaesthesiologist´s classification

Table 2: Preoperative associated comorbidities Variables Number (%)

Congenital heart disease 2 (3.5)

Beckwith wielderman syndrome 2 (3.5)

Intestinal atresia 2 (3.5)

Sepsis 10 (17.5)

Anaemia 3 (5.3)

Jaundice 2 (3.5)

Table 3: Postoperative complications Variables Number (%)

Respiratory distress 6 ( 12.7)

Wound infection 6 ( 12.7)

Burst abdomen 2 ( 3.5)

Persistent hypogylycemia 1 (2.1)

Mortality 14 (16.9)

accepted research article

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